The snake was being diced up to be made into snake soup, which is a delicacy in Guangdong and a much sought after dish in the province's high-end restaurants.

Restaurant guest Lin Sun, 44, who was in the restaurant with his wife Su at the time said: "We were in the restaurant having a meal for my wife's birthday when suddenly there was a lot of commotion.

"We did not know what was happening but could hear screams coming from the kitchen.

"There were calls for a doctor in the restaurant but unfortunately by the time medical assistance arrived the man had already died.

"After we heard that we did not continue with our meal."

Police say Peng died before he could be given life saving anti-venom in hospital. Victims of the Indochinese spitting cobra generally asphyxiate after the neurotoxin paralyses their respiratory system.

A police spokesman said: "It is a highly unusual case but it appears to be just an accident. The man had a very severe reaction to the bite.

"There was nothing that could be done to save the man. Only the anti-venom could have helped but this was not given in time.

"He prepared the snake himself and was just unlucky. It was just a tragic accident."

Snake expert Yang Hong-chang - who has spent 40 years studying cobras - says all reptiles can function for up to an hour after losing body parts, or even their entire body.

"It is perfectly possible that the head remained alive and bit Peng's hand," he said.

"By the time a snake has lost its head, it's effectively dead as basic body functions have ceased, but there is still some reflexive action."

"It means snakes have the capability of biting and injecting venom even after the head has been severed."